
    <!DOCTYPE html>
    <html lang="zh-CN">
    <head>
      <meta charset="UTF-8">
      <meta name="viewport" content="width=device-width, initial-scale=1.0">
      <title>TreeMap和TreeSet在排序元素时是如何进行比较的 - 交互式测验</title>
      <style>
        @import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@400;500;700&display=swap');
        
        body {
          font-family: 'Noto Sans SC', sans-serif;
          background-color: #f4f7f9;
          color: #333;
          display: flex;
          justify-content: center;
          align-items: center;
          min-height: 100vh;
          margin: 0;
          padding: 20px;
          box-sizing: border-box;
        }
        
        .main-wrapper {
            position: relative;
            width: 100%;
            max-width: 900px; /* Wider to accommodate buttons */
            display: flex;
            justify-content: center;
            align-items: center;
        }

        .quiz-container {
          background-color: #ffffff;
          border-radius: 16px;
          box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
          width: 100%;
          max-width: 700px;
          overflow: hidden;
          z-index: 10;
        }

        .quiz-header {
          background-color: #4a90e2;
          color: white;
          padding: 20px 30px;
          text-align: center;
        }

        .quiz-header h1 {
          margin: 0;
          font-size: 24px;
          font-weight: 700;
        }
        
        .quiz-header p {
            margin: 5px 0 0;
            font-size: 14px;
            opacity: 0.9;
        }

        .quiz-body {
          padding: 30px;
        }

        .progress-bar {
            display: none; /* 隐藏进度条 */
            width: 100%;
            background-color: #e0e0e0;
            border-radius: 5px;
            height: 10px;
            margin-bottom: 20px;
        }

        #progress-indicator {
            height: 100%;
            width: 0%;
            background-color: #4caf50;
            border-radius: 5px;
            transition: width 0.3s ease;
        }

        #question-container {
          margin-bottom: 20px;
        }

        #question-text {
          font-size: 18px;
          font-weight: 500;
          line-height: 1.6;
          margin-bottom: 25px;
        }

        .options-list {
          list-style: none;
          padding: 0;
          margin: 0;
        }

        .option-item {
          background-color: #f8f9fa;
          border: 1px solid #dee2e6;
          border-radius: 8px;
          padding: 15px;
          margin-bottom: 12px;
          cursor: pointer;
          transition: background-color 0.2s ease, border-color 0.2s ease;
        }

        .option-item:hover {
          background-color: #e9ecef;
        }
        
        .option-item.selected {
            background-color: #d1e7fd;
            border-color: #4a90e2;
        }

        .quiz-footer {
          padding: 20px 30px;
          display: flex;
          justify-content: space-between; /* 将按钮分布在两侧 */
          align-items: center;
          min-height: 65px; /* Reserve space */
        }

        .nav-btn {
          background-color: #4a90e2;
          color: white;
          border: none;
          border-radius: 8px;
          padding: 10px 20px;
          font-size: 16px;
          font-weight: 500;
          cursor: pointer;
          transition: background-color 0.2s ease, transform 0.2s ease;
          box-shadow: 0 4px 12px rgba(0,0,0,0.15);
        }
        
        #next-btn {
            background-color: #28a745;
        }

        .nav-btn:hover {
          background-color: #357abd;
          transform: scale(1.05);
        }
        
        .nav-btn:disabled {
            background-color: #a0c3e8;
            cursor: not-allowed;
            opacity: 0.7;
        }

        #result-container {
            border-top: 1px solid #eee;
        }
        
        .result-box {
            border-radius: 8px;
            padding: 20px;
            margin-top: 20px;
        }
        
        .result-box.correct {
            background-color: #d4edda;
            border: 1px solid #c3e6cb;
            color: #155724;
        }

        .result-box.incorrect {
            background-color: #f8d7da;
            border: 1px solid #f5c6cb;
            color: #721c24;
        }
        
        .result-box h3 {
            margin-top: 0;
        }

        .explanation-text {
            margin-top: 15px;
            line-height: 1.7;
        }
        
        .source-text {
            font-style: italic;
            font-size: 14px;
            margin-top: 15px;
            color: #555;
        }

        
        .final-score-container {
            padding: 40px;
            text-align: center;
        }
        .final-score-container h2 {
            margin-top: 0;
            margin-bottom: 30px;
        }
        .score-summary {
            display: flex;
            justify-content: center;
            gap: 20px;
            margin-bottom: 40px;
            flex-wrap: wrap;
        }
        .score-card {
            background-color: #f8f9fa;
            border-radius: 12px;
            padding: 20px;
            width: 180px;
            box-shadow: 0 4px 12px rgba(0,0,0,0.05);
            border: 1px solid #e9ecef;
        }
        .score-card h3 {
            margin: 0 0 10px;
            font-size: 16px;
            font-weight: 500;
            color: #555;
        }
        .score-card p {
            margin: 0;
            font-size: 28px;
            font-weight: 700;
            color: #333;
        }
        .score-details table {
            width: 100%;
            font-size: 16px;
        }
        .score-details td {
            padding: 4px 0;
        }
        .score-details td:last-child {
            text-align: right;
            font-weight: 700;
        }
        .report-actions button {
            background-color: #fff;
            border: 1px solid #ccc;
            border-radius: 8px;
            padding: 12px 25px;
            font-size: 16px;
            cursor: pointer;
            margin: 0 10px;
            transition: background-color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
        }
        .report-actions button:hover {
            background-color: #f1f1f1;
            border-color: #bbb;
            transform: translateY(-2px);
        }
        .report-actions button.primary {
            background-color: #28a745;
            color: white;
            border-color: #28a745;
        }
        .report-actions button.primary:hover {
            background-color: #218838;
        }
        
        .hint-container {
            background-color: #e0f7fa;
            border: 1px solid #b2ebf2;
            border-radius: 8px;
            padding: 15px;
            margin-top: 20px;
            color: #006064;
            font-size: 15px;
            line-height: 1.6;
            display: none; /* 默认隐藏 */
        }
      </style>
    </head>
    <body>
      <div class="main-wrapper">
          <div class="quiz-container">
            <div class="quiz-header">
              <h1>TreeMap和TreeSet在排序元素时是如何进行比较的 - 交互式测验</h1>
              <p>检验你对文档内容的理解程度</p>
            </div>
            <div id="quiz-content">
                <div class="quiz-body">
                    <div class="progress-bar">
                        <div id="progress-indicator"></div>
                    </div>
                    <div id="question-container">
                      <p id="question-text"></p>
                      <ul class="options-list" id="options-list"></ul>
                    </div>
                    <div id="result-container"></div>
                    <div id="hint-container" class="hint-container"></div>
                </div>
                <div class="quiz-footer" id="quiz-footer">
                  <button id="prev-btn" class="nav-btn">上一题</button>
                  <button id="hint-btn" class="nav-btn" style="background-color: #ffc107; color: #333; box-shadow: 0 4px 12px rgba(255,193,7,0.3);">提示</button>
                  <button id="next-btn" class="nav-btn">下一题</button>
                </div>
            </div>
          </div>
      </div>

      <script>
        const quizData = [
  {
    "question": "根据文档，`TreeMap` 和 `TreeSet` 最主要的区别是什么？",
    "options": [
      "`TreeMap` 是有序的，而 `TreeSet` 是无序的。",
      "`TreeMap` 存储键值对（key-value pairs），而 `TreeSet` 只存储单一元素。",
      "`TreeMap` 的底层是红黑树，而 `TreeSet` 的底层是哈希表。",
      "`TreeMap` 允许存储 null 键，而 `TreeSet` 不允许。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "文档开篇明确指出，`TreeMap` 和 `TreeSet` 都是基于红黑树的有序集合。它们的主要区别在于数据结构：`TreeMap` 用于存储键值对映射，而 `TreeSet` 用于存储不重复的单一元素集合。实际上，`TreeSet` 的内部实现就是依赖一个 `TreeMap`。",
    "source": "文档开篇第一段",
    "hint": "文档中提到了两者在存储内容上的核心差异：一个是“键值对”，另一个是“单一元素”。"
  },
  {
    "question": "当向一个没有在构造时指定 `Comparator` 的 `TreeSet` 中添加自定义对象时，为了保证其能正常排序，该对象的类必须满足什么前提条件？",
    "options": [
      "该对象的类必须重写 `equals()` 和 `hashCode()` 方法。",
      "该对象的类必须实现 `Serializable` 接口。",
      "该对象的类必须实现 `Comparable` 接口并提供 `compareTo` 方法。",
      "该对象的类必须是 final 类。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "当不提供外部比较器 (`Comparator`) 时，`TreeMap` 和 `TreeSet` 会依赖元素的“自然顺序”进行排序。这种自然顺序是通过让元素的类实现 `Comparable` 接口来定义的，该接口的核心是 `compareTo` 方法，它规定了对象之间如何进行比较。",
    "source": "文档中「1.1. Comparable 接口」部分",
    "hint": "思考一下集合在没有外部排序规则时，会依赖元素自身的什么特性来排序？"
  },
  {
    "question": "在实现 `Comparable<T>` 接口时，其 `compareTo(T other)` 方法返回一个正数通常代表什么含义？",
    "options": [
      "当前对象小于比较对象 (other)。",
      "两个对象相等。",
      "当前对象大于比较对象 (other)。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "`compareTo` 方法的返回值约定如下：返回负数表示当前对象小于参数对象；返回零表示两者相等；返回正数表示当前对象大于参数对象。这是实现自然排序的标准契约。",
    "source": "文档中「1.1. Comparable 接口」部分的列表",
    "hint": "回忆 `compareTo` 方法返回负数、0、正数分别对应的三种比较结果。"
  },
  {
    "question": "与 `Comparable` 接口相比，使用 `Comparator` 接口进行排序最主要的优势是什么？",
    "options": [
      "`Comparator` 的执行性能总是优于 `Comparable`。",
      "它允许在不修改对象类本身的情况下，为同一类型的对象定义多种不同的、灵活的排序规则。",
      "只有 `Comparator` 才能实现降序排序。",
      "`Comparator` 是 Java 集合框架中唯一的排序方式。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "`Comparator` 的设计体现了策略模式，它将比较逻辑从业务对象中分离出来。这带来了极大的灵活性，我们可以根据不同场景创建不同的比较器（如按姓名排序、按年龄排序），而无需侵入和修改 `Student` 类本身。",
    "source": "文档中「1.2. Comparator 接口」部分",
    "hint": "文档中提到 `Comparator` 更“灵活”，想一想这种灵活性体现在哪里？"
  },
  {
    "question": "一个 `TreeMap` 集合在进行内部排序时，其排序依据是什么？",
    "options": [
      "根据键值对（Entry）的哈希码。",
      "根据元素的插入顺序。",
      "根据值（Value）的自然顺序。",
      "根据键（Key）的比较结果（自然顺序或自定义比较器）。"
    ],
    "correctAnswerIndex": 3,
    "explanation": "`TreeMap` 是一个基于其键（Key）排序的映射。无论是插入、查找还是删除操作，都是通过比较键来定位的。值（Value）不参与 `TreeMap` 的排序过程。",
    "source": "文档中「2. TreeMap 的排序机制」和「4. TreeMap 和 TreeSet 的排序细节」部分",
    "hint": "在 `studentMap.put(student, \"A班\")` 这样的操作中，哪一部分决定了元素在 Map 中的位置？"
  },
  {
    "question": "根据文档所述，`TreeMap` 和 `TreeSet` 的底层数据结构及其带来的时间复杂度是什么？",
    "options": [
      "哈希表（Hash Table），平均时间复杂度为 O(1)。",
      "红黑树（Red-Black Tree），插入、删除和查找的时间复杂度为 O(log n)。",
      "双向链表（Doubly Linked List），插入和删除的时间复杂度为 O(1)。",
      "数组（Array），查找时间复杂度为 O(n)。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "文档明确指出 `TreeMap` 和 `TreeSet` 都是基于红黑树实现的。红黑树是一种自平衡的二叉查找树，它能确保树的高度大致保持在 log n 的级别，从而保证了增、删、查等关键操作都具有 O(log n) 的高效时间复杂度。",
    "source": "文档中「4. TreeMap 和 TreeSet 的排序细节」部分的第3点",
    "hint": "文档中提到了一个能“保持其平衡状态”的数据结构，它保证了关键操作的效率。"
  },
  {
    "question": "假设 `Student` 类通过实现 `Comparable` 接口定义了按成绩（score）的自然排序。如果现在需要创建一个 `TreeMap` 来按学生姓名（name）排序，最恰当的做法是什么？",
    "options": [
      "先将所有学生存入 `ArrayList`，使用 `Collections.sort` 按姓名排序后，再逐个放入 `TreeMap`。",
      "修改 `Student` 类中的 `compareTo` 方法，使其按姓名排序。",
      "在创建 `TreeMap` 时，向其构造函数传入一个按姓名排序的 `Comparator` 实例。",
      "这是无法实现的，因为 `Comparable` 定义的自然顺序优先级最高。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "当元素的自然顺序不符合当前需求时，最佳实践是提供一个外部比较器 (`Comparator`)。`TreeMap` 和 `TreeSet` 的构造函数接受一个 `Comparator` 作为参数，这个比较器的优先级会高于元素自身的自然顺序，从而实现自定义排序，且不影响 `Student` 类的原有设计。",
    "source": "文档中「2. TreeMap 的排序机制」部分的末尾示例",
    "hint": "思考一下如何在不改变一个类的“默认”排序行为的情况下，实现一种“临时”或“特定场景”的排序规则？"
  }
];
        console.log("Quiz Data:", JSON.parse(JSON.stringify(quizData))); // 添加这行用于调试，以可展开的JSON格式输出
        
        let currentQuestionIndex = 0;
        let score = 0;
        // 存储每个问题的回答状态
        const userAnswers = new Array(quizData.length).fill(null); 

        const questionTextEl = document.getElementById('question-text');
        const optionsListEl = document.getElementById('options-list');
        const resultContainerEl = document.getElementById('result-container');
        const quizContentEl = document.getElementById('quiz-content');
        const progressIndicatorEl = document.getElementById('progress-indicator');
        const prevBtn = document.getElementById('prev-btn');
        const nextBtn = document.getElementById('next-btn');
        const hintBtn = document.getElementById('hint-btn');
        const hintContainerEl = document.getElementById('hint-container');

        function loadQuestion() {
          resultContainerEl.innerHTML = '';
          optionsListEl.innerHTML = '';
          hintContainerEl.style.display = 'none'; // 隐藏提示
          
          if (currentQuestionIndex >= quizData.length) {
            showFinalScore();
            return;
          }

          updateProgress();

          const currentQuestion = quizData[currentQuestionIndex];
          questionTextEl.textContent = `(${currentQuestionIndex + 1}/${quizData.length}) ${currentQuestion.question}`;
          
          currentQuestion.options.forEach((optionText, index) => {
            const li = document.createElement('li');
            li.className = 'option-item';
            li.textContent = optionText;
            li.dataset.index = index; // Store index in a data attribute
            // 如果这道题已经回答过，恢复状态
            if (userAnswers[currentQuestionIndex] !== null) {
                if (index === userAnswers[currentQuestionIndex]) {
                    li.classList.add('selected');
                }
            }
            optionsListEl.appendChild(li);
          });

          // 如果已经回答过，直接显示结果
          if (userAnswers[currentQuestionIndex] !== null) {
              const isCorrect = userAnswers[currentQuestionIndex] === currentQuestion.correctAnswerIndex;
              showResult(isCorrect, currentQuestion);
          }
          
          updateNavigationButtons();
          updateProgress();
        }

        function selectOption(optionIndex) {
            userAnswers[currentQuestionIndex] = optionIndex;
            const currentQuestion = quizData[currentQuestionIndex];
            const isCorrect = optionIndex === currentQuestion.correctAnswerIndex;

            // 重新计算分数
            score = userAnswers.reduce((acc, answer, index) => {
                return answer === quizData[index].correctAnswerIndex ? acc + 1 : acc;
            }, 0);

            showResult(isCorrect, currentQuestion);
            updateNavigationButtons();
        }
        
        function updateProgress() {
            const answeredQuestions = userAnswers.filter(answer => answer !== null).length;
            const progressPercentage = (answeredQuestions / quizData.length) * 100;
            progressIndicatorEl.style.width = `${progressPercentage}%`;
        }
        
        function updateNavigationButtons() {
            prevBtn.style.display = 'block';
            nextBtn.style.display = 'block';
            hintBtn.style.display = 'block'; // 显示提示按钮

            prevBtn.disabled = currentQuestionIndex === 0;
            nextBtn.disabled = false; // 最后一题时，下一题按钮不禁用，而是用于显示报告
            nextBtn.textContent = (currentQuestionIndex === quizData.length - 1) ? '查看报告' : '下一题';
            
            // 如果当前问题没有提示，则禁用提示按钮并隐藏提示内容
            if (!quizData[currentQuestionIndex].hint) {
                hintBtn.disabled = true;
                hintContainerEl.style.display = 'none';
                hintContainerEl.textContent = ''; // 清除旧的提示内容
            } else {
                hintBtn.disabled = false;
            }
        }

        function showResult(isCorrect, questionData) {
            resultContainerEl.innerHTML = ''; // 清空之前的结果
            const resultBox = document.createElement('div');
            resultBox.className = `result-box ${isCorrect ? 'correct' : 'incorrect'}`;
            
            let html = `<h3>${isCorrect ? '回答正确！' : '回答错误'}</h3>`;
            if (!isCorrect) {
                html += `<p><strong>正确答案是：</strong> ${questionData.options[questionData.correctAnswerIndex]}</p>`;
            }
            html += `<div class="explanation-text">${questionData.explanation}</div>`;
            html += `<div class="source-text">来源: ${questionData.source}</div>`;
            
            resultBox.innerHTML = html;
            resultContainerEl.appendChild(resultBox);

            // 禁用所有选项的点击事件，并高亮正确/错误答案
            Array.from(optionsListEl.children).forEach((child, index) => {
                child.style.pointerEvents = 'none';
                // 高亮正确答案
                if (index === questionData.correctAnswerIndex) {
                    child.classList.add('correct'); // 需要添加CSS样式
                    child.style.backgroundColor = '#d4edda';
                    child.style.borderColor = '#c3e6cb';
                }
                // 如果选错了，高亮错误选项
                if (!isCorrect && index === userAnswers[currentQuestionIndex]) {
                    child.classList.add('incorrect'); // 需要添加CSS样式
                    child.style.backgroundColor = '#f8d7da';
                    child.style.borderColor = '#f5c6cb';
                }
            });
        }

        function goToNextQuestion() {
            if (currentQuestionIndex < quizData.length - 1) {
                currentQuestionIndex++;
                loadQuestion();
            } else {
                showFinalScore();
            }
        }

        function goToPreviousQuestion() {
            if (currentQuestionIndex > 0) {
                currentQuestionIndex--;
                loadQuestion();
            }
        }
        
        function showHint() {
            const currentQuestion = quizData[currentQuestionIndex];
            if (currentQuestion.hint) {
                hintContainerEl.textContent = currentQuestion.hint;
                hintContainerEl.style.display = 'block';
            } else {
                hintContainerEl.style.display = 'none';
            }
        }

        function showFinalScore() {
            document.querySelector('.quiz-body').style.display = 'none';
            document.getElementById('quiz-footer').style.display = 'none';

            const correctCount = score;
            const totalQuestions = quizData.length;
            const answeredCount = userAnswers.filter(a => a !== null).length;
            const wrongCount = answeredCount - correctCount;
            const skippedCount = totalQuestions - answeredCount;
            const accuracy = totalQuestions > 0 ? Math.round((correctCount / totalQuestions) * 100) : 0;
            const errorRate = totalQuestions > 0 ? Math.round((wrongCount / totalQuestions) * 100) : 0;

            const finalScoreHtml =
                '<div class="final-score-container">' +
                '<h2>答题报告</h2>' +
                '<div class="score-summary">' +
                '<div class="score-card">' +
                '<h3>得分</h3>' +
                '<p>' + correctCount + ' / ' + totalQuestions + '</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>正确率</h3>' +
                '<p>' + accuracy + '%</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>错误率</h3>' +
                '<p>' + errorRate + '%</p>' +
                '</div>' +
                '<div class="score-card score-details">' +
                '<table>' +
                '<tr><td>正确</td><td>' + correctCount + '</td></tr>' +
                '<tr><td>错误</td><td>' + wrongCount + '</td></tr>' +
                '<tr><td>未答</td><td>' + skippedCount + '</td></tr>' +
                '</table>' +
                '</div>' +
                '</div>' +
                '<div class="report-actions">' +
                '<button id="review-btn">回顾测验</button>' +
                '<button class="primary" onclick="location.reload()">再试一次</button>' +
                '</div>' +
                '</div>';

            let reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }
            quizContentEl.insertAdjacentHTML('beforeend', finalScoreHtml);
            document.getElementById('review-btn').addEventListener('click', reviewQuiz);
        }

        function reviewQuiz() {
            const reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }

            document.querySelector('.quiz-body').style.display = 'block';
            document.getElementById('quiz-footer').style.display = 'flex';
            
            currentQuestionIndex = 0;
            loadQuestion();
            updateNavigationButtons(); // Ensure nav buttons are correctly displayed
        }

        // Event Delegation for options
        optionsListEl.addEventListener('click', (event) => {
            if (event.target && event.target.matches('li.option-item')) {
                // Check if the question has already been answered
                if (userAnswers[currentQuestionIndex] === null) {
                    const selectedIndex = parseInt(event.target.dataset.index, 10);
                    selectOption(selectedIndex);
                }
            }
        });

        prevBtn.addEventListener('click', goToPreviousQuestion);
        nextBtn.addEventListener('click', goToNextQuestion);
        hintBtn.addEventListener('click', showHint);
        
        // 初始加载
        loadQuestion();
      </script>
    </body>
    </html>
  